Class XI

Three thin uniform rods each of mass M and length L are placed along the three axis of a Cartesian coordinate system with one end of each rod at the origin. The M.I. of the system about z- axis is

ML2

ML2ML2/6

ML2ML2/3

(2/3) ML2

A uniform rod of mass 2 kg is 1 meter long. Its radius of gyration about an axis through its one end and perpendicular to its length in SI units is

1/ 2√√ (3)

2/3

1/√√ (3)

2 /√√ (3)

a body is rotating about z axis with a speed ωω and a point is at a distance of r in the x-y plane then the velocity of the point is

rω

3rω

rω/2

2rω

Angular acceleration vector is defined as

α = 2 dω dt

α = d ω 2 dt2

α = dω dt

α = d ω 3 dt3

The moment of inertia of a body about any axis is

equal to the sum of the moment of inertia of the body about a parallel axis passing through its centre of mass and the product of its mass and the square of the distance between the two parallel axes.

equal to the difference of the moment of inertia of the body about a parallel axis passing through its centre of mass and the product of its mass and the square of the distance between the two parallel axes.

equal to the average of the moments of inertia of the body about a parallel axis passing through its centre of mass and the product of its mass and the square of the distance between the two parallel axes.

equal to the sum of the moment of inertia of the body about any axis passing through its centre of mass and the product of its mass and the square of the distance between the two parallel axes.